Percussion and hydrostatic fuse



Dec. 4, 1928. 1,693,661

IA. OGDEN PERCUSSION AND HYDROSTATIC FUSE Filed July '7. 1926 2Sheets-SheetI l ELS.

Bec. 4, 1928.A

Fil

'A. OGDEN PERCUSSION AND HYDROSTATIC FUSE ad July 7, 1926 2 Sheets-Sheet2 n INVENTO? BY l bw HTTO/NEYJ Patented Dec. 4, 1928.

UNITED STATES APATENT- oFFlcE.

AMOS OGDEN, 0F BARROW-IN-FURNESS, ENGLAND, ASSIGNOR T0 VICKERS LIMITED,

OF WESTMINSTER, ENGLAND, A BRITISH COMPANY. Y .l

PERCUSSION AND HYDRIOSTATIG FUSE.

Application led July 7, 1926, Serial No. 120,924, and in Great BritainNovember 26, 1925.

This invention relates to. bombs adapted to be dropped from aircraft andmore particularly to improvements in the impact mechanism of such bombs,with the object of increasing their efficiency in attack. The bombs areprovided with improved hydrostatically operated firing mechanism so thatthey may also serve as depth charges.

According to this invention the bomb is provided at its lower end withmeans by which it is adapted on impact to penetrate an obstruction ofmoderate strength, such as the non-protective deck of a vessel, withoutoperating the impact firing mechanism, whereupon the bomb is rendere-dcapable of firing on meeting the next obstacle. The penetrating memberis preferably in the form of a pointed nose piece carried in adetachable manner by the bomb and having a tubular shank extending overthe outer end of an impact firing rod, the penetrating member beingsecured in position in the nose of the bomb by a spring clip orequivalent device which after the light deck or other minor obstructionhas been penetrated allows the penetrating member to iiy od, owing tothe momentary check given to the body of the bomb on striking theobstruction, whereupon thc impact firing rod is left exposed w and thebomb is fired when the rod meets the second deck or next obstruct-ion.If, however, the bomb strikes a protective deck or the amouring of avessel, the penetrating member is driven back together with the impactrod and t-he bomb is fired instantaneously.

In order that the said invention may be clearly understood and readilycarried into effect, the same will now be described more fully withreference to the accompanying drawings in which Fig. 1 shows inlongitudinal section a bomb embodyingv this invention, and Figs. 2 and 3are similar views to a larger scale of the main portion of theapparatus.

A, A are the two main casing members of the bomb, the member A being .ofgreater thickness and forming the nose or lower end of the bomb, thecasing containing the charge B. C is a central tube extending from endto end of the bomb, and open to the water through channels a. D is theimpact detonator of the bomb mounted on a tubular carrier Z slidingwithin the impact pistol E. F is the penetrating member mounted in thenose of the bomb. G is a primer fitted slidably or floating Within aguide tube H mounted in the central tube C. J is a depth charge pistolwith detonator j, the depth charge pistol being fired at the desireddepth, in the event of the bomb serving as a depth charge, by means ofthe pistol K.

In the construction of impact firing ap aratus illustrated the detonatorD on the sllding carrier d is fired by a firing pin e in the pistolcasing E. The ring pin I1s held back by a spring e which extends lntothe tubular carrier d and abuts against the collar or nut e2 on therea'r end of the firing pin, the spring e normally holding thefiringzpin-well away from the detonator D in the position shown in thedrawing. The firing pin is mounted in the tubular carrier e3 withinwhich the detonator carrier d slides. Shoulders d and e4 limit therelative movement of the car-A riers e3 and Z and shoulders e5, and elimit the movement'of the carrier es in the casing E. Impact ring iseffected by the impact firing rod L which is formed with a headZ slidingin the outer end of the pistol casing VE and spaced a short distancefrom the lower or outer end of the firing pin e, a strong spring Zmaintaining the head of the firing rod against a fixed iianged ring mcarried at the inner end of the nose piece M supporting the impact rod Land thepenetrating member F. Water can pass freely into the interior ofthe centre tube C through the openings a in the nose of the-bomb, if thebomb is ldropped into water.

-On the 'impact rod L being forced back it rst meets the collar e2 onthe lower end of the firing pin and drives the, latter back 'against thespring e. The primer G is ioating or slidably mounted in the guide tubeH and on the bomb meeting an obstruction the primer moves. down by itsmomentum and forces back the detonator carrier d. The end of the primerG is provided with a small central recesslg into which the detonator Dprojects so that the detonator is not forced back until the end of theprimer reaches the detonator carrier d. The detonator can be fired,however, only lif the striking o'dalso forces up the firing pin e, sothat firing takes place only by the combined movement due to the firingrod andthe primer and the shoull ders e4, e5, e6 of the pistol E are soarrangedthat neither of these -two movements sepaj rately can effect thefiring. v

Itv will be seen especially in Figure 2 that the detonator carrier dwhen pushed fully back does not bring the detonator D into contact Withthe firing pin when the latter is in the position shown, but if thestriking rod L is at the same time driven back carrying with it thefiring pin e the firing piu and detonator come into contact an-d thebomb is explode-d. If on the other hand the firing pin only is pushedback until the shoulders e5 and eG meet movement of the firing pinlimited by these shoulders is not sufficient to bring the pin intocontact with the detonator D, the spacing of the various shoulders beingsuch that the individual movements permitted to the detonator and thefiring pin would not unless combined enable the striking pin to reachthe detonator.

It Will be seen that the impact rod L is prevented from operation aslong as the penetrating member F is in the position shown in thedrawing, the penetrating member being secured in the nose M of the bombby the spring clip f, which in the construction illustrated comprises apair of springs mounted in grooves f in the tubular shank f2 of thepenetrating member and having bent ends which extend into the annulargroove m of the nose piece M. The penetrating member F, if the bombdrops on to a relatively slight obstruction `such. for example, as thelight deck of a vessel, passes through the deck and prevents firing ofthe bomb during the penetration of the deck by the member F and theheavy bomb, While the slight check to the bomb given by the resistance othe deck to the large surface of the nose A1 of the bomb causes themember F Which has been substantially unchecked on penetrating to flyolf the nose of the bomb and leave the impact rod L exposed. With thepenetrating member F absent the rod L on meeting the second obstructionis forced back and as the primer has already driven back the detonator Dthe tiring pin e on being forced back by the rod L explodes thedetonator and res the bomb.

While the penetrating member F prevents firing of the bomb as long as itmaintains its forward position should the bomb strike any heavyobstruction such as a protective deck or the covering of a vessel, theforce of impact drives back the member F, which is held in position by ashearing ring m2 fitted inside the nose piece vM behind a ring m3against which the inner end of the penetrating member F abuts, thevshearing ring m2 being of sulicient strength to hold the penetratingmember in position for any relatlvely slight obstruction, while if theresistance on impact is sufficiently great the shearing ring yields andthe penetrating member F together with the impact rod L is forced backand instantaneous firing is e'ected by the combined operation of thepenetratin member, firing rod andprimer. The s caring ring m2 orequivalent resisting member can be set to prevent yielding andconsequent ring up to any desired impact resistance.

The bomb is, of course, not fired on striking the surface of Water butpenetrates it until a hydrostatically operated or depth charge pistol isactuated. The hydrostatic mechanism may be on the lines described in thespecifications of applications for patent Serial Nos. 59.808, filedOctober 1, 1925, and 99,695, filed April 5, 1926, especially the latter,in which the construction of the upper end of the present bomb isdescribed. The depth charge pistol J is stationary and is cocked andfired by the hydrostatically operated piston co-operating with thesliding or floating primer unit G Which is also subjected to thepressure of the Water. A recess g at the upper or rear end of the primerreceives the detonator y'.

In the arrangement shown the depth charge pistol J is rigidly attachedto the guide tube H (formed in two parts) While the regulator or pistonK is movable Within the tube, under the influence of the hydrostaticpressure, relatively to the primer unit G.

The depth regulator K is provided with two auxiliary air chambers 7c and1", in addition to the main a'ir chamber N, the main air chamber N beinglocated on each side of the pistol J and a passage j being provided toplace the two parts of the chamber N in communication with one another.

The depth regulator K and the primer unit G are provided With rubberrings k2 and g2 between them and the tube H Within Which they areslidably mounted. The rubber rings maintain an airtight joint While atthe same time they give very little resistance to movement. By means ofthese rubber rings a volume of air is trapped between the primer unit Gand .the depth regulator K which has to be compressed before these tWomembers can move into a position at which they jointly operate the depthcharge pistol J. The external water pressure and the internal airpressure will at any given depth be substantially the same, thehydrostatic pressure being slightly greater so as to overcome the slightfriction. There is, therefore, no tendency for air to leak out and dueto the slight difference of pressure the rubber rings effectuallyprevent Water from leaking in- Wards. The initial air volume and thefinal compression volume provided for the purpose of regulating thedepth at which firing is to take place is adjusted in advance by cuttingolf the volumes/7c and k by means of a rotary valve O from communicationthrough the passages 0, o, o2 and 03 with the main air chamber N.

The hydrostatically operated piston K is open to the pressure of theWater at its outer end so that should the bomb fall into Water thepiston is acted upon by an increasing water pressure as the bomb sinks,compressing the air in the' space N immediately in front of the iston,the back pressure of. the compressed air determining the movement of thepiston with relation to the hydrostatic pressure as the depth increases.At

the same time the Water is free to enter the space in the tube C causingpressure inside the guide tube in the annular space surrounding 1t andalso around the p-rimer G, water entering through the nose of the bombinto the guide tube through the apertures a as already mentioned.

In the arrangement shown the depth charge is adapted to lire at 30, 120and 180 feet. In

order to fire at 30 feet the additional volumes 7c and k are opened tothe central working volume N; to fire at 120 feet the volume 7c 1s cutoff; to fire at 180 feet the volumesc and lc are cut off. When, however,the

depth charge has reached the depth at which automatic firing is to takeplace and is subjected to a hydrostatic pressure corresponding to anyone of the said set depths the depth regulator or piston K is pushedinwards until it strikes the pistol J and moves inwards the part j2 soas partiallyI to compress the spring ya.

At the same time the primer unit G has also been moved inwards by thehydrostatic pressure along the guide tube' H. until it contacts with theshoulder jt* and pushes in the detonator support 75 also compressing thespring i3. When both these movements are completed the balls P of a ballreleasing device of common constructionare free to move radiallyoutwards thus releasing the striker j which moves forward and lires thedetonator j. It will be clear that the pistol cannot operate until boththe depth regu-` lator and the primer units are simultaneouslypushed into the centre of the guide tube. Should the primer unit or the depthregu-y lator move in separately, for example owing to inertia, the depthcharge cannot accidentally be exploded as the pistol can only beoperated by the hydrostatic pressure actingsimultaneously on both units.

What I claim and desire to secure by Letters Patent of the United Statesis 1. In a bomb, impact firing mechanism adapted to be ired on strikingthe obstacle, means whereby the bomb is prevented from exploding onstriking a solid obstacle offering a relatively small resistance, whichmeans are rendered inoperative upon such obstacle being struck, andmeans whereby the bomb is then exploded upon meeting a further obstacle.

2. In a bomb, impact tiring mechanism, and means for preventing the saidfiring mechanism exploding the bomb on the latter striking a solidobstacle offering a relatively small resistance, which preventive meansare rendered inoperative after such obstacle is struction. penetrated bythe said member and struck, whereupon the said impact firingA mechanismcan explode the bomb upon meetl for retaining the penetrating member inyposition and for enabling it to release itself from the bomb on thelatter meeting an o bimpact irmg mechanism protected from operation bythe saidpenetrating member while the latter is in position on the bomb.

4:. In a bomb, a pointed nose piece detachably `moimted at the end ofthe bomb, a clip retaining the said nose piece in positlon but lallowingit to free itself from the bomb by momentum, an impact rod the' forwardend of which is covered and protected by' the pointed nose piece butoperated on meetin an obstruction after the detachment of the said nosepiece and firing mechanism adaptedl vto be operated by the said impactrod.

5. Iny a bomb, a penetrating member mounted at the lower end of thebomb, means for retaining the penetrating member in position and forenabling it to releaseV itself from the bomb on the latter meeting an'obstruction penetrated by the said member, impact firing mechanismprotected from operation by the said pentrating member while the latteris in position'on the bomb, means for supporting the said penetratingmember,

on impact, against a predetermined impact force, which means yield toallow the said penetrating member to be driven back and' to operate thefiring mechanism if the impact force exceeds the predetermined amount.6. In a bomb, a penetrating member mounted at the lower end'of the bomb,means 105 for retaining the penetrating member in positionv andi'orenabling it to release itself 'from the bomb on' the latter meeting anobstruction penetrated by the said member, im- L. pact ringfmechanismprotected from operllo ation by the said penetrating member while' thelatter i'sin position on the bomb, a shearing member mounted in the nosevof the 4bomb` l l behind :theISad penetrating member andl adapted tobesheared by impact pressure on A the penetratingv member above vapredetermined amount.

k7. In a bomb, a pointed penetrating member havingv a tubular shankmounted in the nose of the bomb, afclip device retaining the 12 saidtubular shank in position but adapted to free the said penetratingmember from the nose of the bomb on any check to its fall being given tothe bomb after the penetrating member haspierced an obstacle, an impact125 rod extending into the tubular shank and yprotected by thepenetrating member when in position and firing mechanism adapted tov beoperated by the said impact rod when the latter is forced back onmpact.-

70 mounted at the lower end' of the bomb, means 8. In a bomb, a primerunit slidably mounted Within the bomb and adapted to move down onimpact, an impact member at the nose of said bomb and firing mechanismoperated jointlyl by the primer unit and impact member, t e said firingmechanism bcing inoperative unless both the primer unit and theaforesaid impact member combine to actuate the tiring mechanism.

9. In a bomb, impact firing mechanism including a detonator and animpact operated firing pin, and a primer unit slidabl y mounted insidethe bomb and adapted on impact of the bomb to move forward for actuationof a part of the said firing mechanism so as to bring the firing pin anddetonator into cooperative relation to enable the ring mechanism to act.

10. In a bomb, the firing mechanism comprising a slidably mounteddetonator, a firing pin, resilient means for maintaining the detonatorand firing pin in spaced relation, an external impact member adaptedonmeeting an obstacle to actuate a portion of the firing mechanism todecrease the space between the detonator and firing pin and an internalmember adapted on impact to actuate a second member of the firingmechanism also to decrease the space between the detonator and firingpin, the firing pin meeting the detonator only if both of the saidmembers have co-operated to actuate the tiring mechamsm.

11. In a bomb, impact ring mechanism comprising an impact pistol casing,a detonator, a tubular etonator carrier adapted to slide in the saidpistol casing, a firing pin, a second tubular carrier for the saidfiring pin also adapted to slide in the pistol casing, a spring normallymaintaining the two sliding tubular carriers in inoperative relativeposition and two sliding members adapted on impact to act separatelyupon the two tubular carriers, the iring pin being caused to strike thedetonator only on the co-operative action of both the sliding members.

movable within the said bomb to co-operate with either the impact firingmechanism or the hydrostatically operated firing mechamsm.

13. In a bomb, impact firing mechanism fitted in the noso of the bomb,hydrostatically operated firing mechanism open to the water at the rearof the bomb and a sliding primer unit exposed, on the bomb being droppedinto Water, to water pressure at one. end and to co-operate with thehydrostatically actuated firing mechanism and adapted, on the otherhand, to co-operate With the impact firing mechanism on impact of thebomb upon a solid obstruction.

14. In a bomb as claimed in claim 8, hydrostatically operated firingmechanism in which the said rimer unit co-operates to actuate the saidring mechanism whereby the bomb will serve as a depth charge.

15. In a bomb, impact firing mechanism comprising an impact pistolhaving a detonator mounted slidably therein, an impact member adapted tooperate a part of the impact pistol, a primer unit slidably mounted andon moving adapted to co-operate with the said impact member and having arecessed end receiving the detonator on movement of the primer by impactof the bomb, the primer unit on further movement pressing back thedetonator carrier and co-operating in the firing of the detonator.

16. In a bomb provided both with impact and hydrostaticall operated ringdevices, a primer unit slida ly mounted Within a tube in the bomb, and amovable sealing ring interposed between the primer unit and its guidetube whereby the primer unit can serve as a piston under water pressurewhen the bomb is used as a depth charge.

AMOS OGDEN.

